With Gordon Brown almost certain to take over as prime minister this year, and his reputation for springing surprises, people in the health service are beginning to wonder what it will mean for them and the NHS reform landscape. Daniel Martin looks for clues

Gordon Brown likes to spring surprises. Less than a week after becoming chancellor in 1997, he shocked the political establishment by proposing the independence of the Bank of England.

Now his aides are promising something spectacular at some point during his first 100 days as prime minister. For unless he falls under a political bus, Gordon Brown will take over from Tony Blair at some point before the autumn.

So what should the NHS expect from a prime minister who is known not to be too interested in health, but who as chancellor has had a massive impact on NHS progress during the past 10 years?

'My fear is that he'll want to make his mark,' says NHS Alliance chair Dr Michael Dixon. 'The NHS doesn't need change at the moment and it's a shame there's this big political change in the offing. Any upheaval could be hugely damaging.'

But, despite all the talk of surprises, there are many who believe that Mr Brown as PM might be startlingly similar to Mr Blair, from an NHS standpoint.

There will be strong arguments in favour of stability. The election is looming; some believe a snap poll could be called as early as this year. Not perhaps the best time to destabilise the health service.

'I'd expect Brown to take a pragmatic approach,' says King's Fund chief executive Niall Dickson. 'He will not want to be seen undoing too much Blair stuff because that would look odd, seeing as he's been so closely involved with it.'

The problem in working out what a Brown premiership will be like is that the chancellor is known to be far less interested in health than areas like education and child poverty. He has barely mentioned it in big Commons set-pieces like the recent pre-budget report. Apart from sketchy proposals last year to give the NHS some form of independence, he has been silent on the subject. Whitehall insiders believe he has not even thought about it yet.

That is not to say he has not had a big impact on the NHS over the past decade. When he agreed to step aside for Tony Blair in the race to be Labour leader, he demanded that if the party won power he would have far greater control over social policy than most chancellors.

It was Mr Brown who insisted that the newly elected government stick to Tory spending plans on the NHS, and it was a Treasury-commissioned report, carried out by former banker Sir Derek Wanless, that set out the case for greater investment in health (although this had already been signalled by Mr Blair in an unscripted promise on Breakfast with Frost).

Mr Brown has also been one of the most fierce proponents of the private finance initiative, which has been used to fund massive hospital building programmes.

The problem with working out how a Brown premiership may shape up is untangling what policies have been pushed by Number 10 and which have been put forward by Number 11.

And what does this tell us about the future anyway? As Mr Dickson says: 'Gordon Brown as chancellor and Gordon Brown as prime minister in waiting are not the same thing as Gordon Brown the prime minister.'

Over the years, perceived policy differences have grown up between the pair. Mr Brown is generally associated with the 'target culture' - it was his Treasury that set the challenging public service agreements with government departments that led to the accident and emergency and 18-week targets.

Mr Blair on the other hand is linked with the entry of the private sector to introduce competition and drive up performance - a policy with which Mr Brown has been uneasy. This may colour his approach to the NHS once he moves next door.

'Blair has been pushing on the issue of bringing the independent sector into health much more than Brown has,' says Mr Dickson. 'It leaves us unsure about just how committed a Brown government would be to market-style reforms.

'It doesn't mean they're going to be abandoned: but it does mean they may slow down on some aspects.'

Foundation fears

Any rowing back on Blairite reforms would be fiendishly difficult. The prime minister has been working hard to preserve his legacy; and many of his NHS reforms are so embedded that it would be next to impossible for Mr Brown to reverse them - even those with which he disagreed when they were first floated.

The highest profile argument between Number 10 and Number 11 was perhaps over foundation trusts, which were brought in under then health secretary Alan Milburn even though Mr Brown was worried about the effect their independence would have on public finance.

But with 54 acutes now having attained foundation status, and 70 more expected to do so within the next year, it is too late to step back. And foundations have proved themselves to be rather successful, achieving higher ratings and generally more impressive financial positions than non-foundations.

Even community foundation trusts, the new kids on the block, are likely to be well into the pilot stage by the time Mr Brown comes to power.

The other Blairite policy about which Mr Brown was sceptical was choice of provider and the introduction of market elements in the NHS. For reasons of equity he was unsure of the benefits of choice: like many he was concerned that it would give middle class voters more say over their healthcare than the working classes, widening the so-called health deficit.

A question of pace

But, as the policy has bedded in, it has become less and less reversible. Mr Brown won't turn back, but there is some question over the speed with which he might pursue change.

If they hit a sticky patch, will Mr Brown be as steady as Mr Blair at sticking with the reforms? If acute trusts get into real financial difficulties, will he be more likely than Blair would have been to suspend the tariff or rewrite it in acutes' favour? Will he hold firm in the belief that services need to be moved to the community, even though it is often hard to persuade a sceptical public of that? Will he continue paying over the odds for independent treatment centres?

There are many who believe Gordon Brown will slow down the reform bandwagon at the first sign of trouble. He could, for example, reverse the ban on strategic health authorities top-slicing funds from high-performing trusts and giving them directly to those in trouble, as a way to avoid damaging and politically dangerous cuts.

But although we might not see any great shifts in principle, we might see changes of emphasis.

Value for money will undoubtedly be a key mantra for prime minister Brown. Chancellor Brown and his Treasury team have been watching the perceived failure of the NHS to spend its Wanless bounty effectively with mounting concern. He is likely to increase pressure on the service to improve its productivity; squeezing every last penny out of each pound to prove to him and the voters that the extra investment has been worth it.

He is said to be particularly alarmed with the triple whammy of the GP, consultant and nurses' contracts, which have seen many NHS staff taking home more money in return for little more - and in many cases less - work. It is likely that the unions will find it a great deal harder in future to persuade the Department of Health to offer similarly generous deals.

Again with his eye on the purse, Brown is expected to make public health, an area which has been squeezed during the financial problems experienced by the NHS over the past couple of years, a much higher priority.

He will want to see greater investment in improving the long-term health of the nation to enable money to be saved in the long run. 'There will be a much bigger concentration on, for example, reducing the rising levels of obesity and making sure that PCTs are doing everything they can to tackle health inequalities in their areas,' says Professor Chris Ham, director of Birmingham University's health services management centre.

Greater concentration on public health will also help the NHS tackle one of Brown's biggest gripes: health inequalities. A big push on this would sit well alongside his campaign for better education to lift people out of poverty.

When Mr Brown made his pre-Budget report last month, the only mention of health was the establishment of a new organisation to co-ordinate health research and bring together the work of the National Institute for Health Research, the Medical Research Council and DoH researchers.

It is a sign of what will be one of Mr Brown's biggest priorities: science and technology. He wants to see Britain at the cutting edge of the 'white heat' of the technical revolution - particularly when it comes to medical research. It is understood he wants to create a powerful new ministry of science by breaking up the Department of Trade and Industry.

Independent minded

One should not lose sight of the personal angle in all of this. Mr Brown has wide experience of the great work the NHS can do, at least in Scotland. His first child Jennifer died despite the valiant efforts of hospital staff. And his third child Fraser was recently diagnosed with cystic fibrosis. The condition is untreatable at the moment, but scientists are making huge progress. Mr Brown will want to do all he can to help them in their race to cure this and other diseases.

And who can discount the possibility that once he takes over he will want to tackle one big difference between the English and Scottish NHS: while in Scotland babies are screened for cystic fibrosis as a matter of course, this is not always the case in England.

As part of Mr Brown's drive to push forward medical research, he is also said to be interested in giving clinicians a greater say over the future of the NHS. This is likely to have been at the forefront of his mind when his aides floated the idea of an independent board to run the NHS along the lines of the Bank of England or, more likely, the BBC. However, handing over such a large budget and politically sensitive area to an independent board would be a huge and possibly irreversible step.

Many are sceptical: could we really expect the man who imposed the centrally defined targets on the DoH and opposed foundation hospital freedom to give the NHS more independence? The word in the DoH is that this policy has 'gone off the boil'.

Handing over policy-making to an independent board would be a revolution. Few in the NHS are expecting that from Mr Brown. The most many expect is organic change.

As Mr Dickson says: 'Those who believe a Gordon Brown premiership will be a white charger waving a red flag will be sorely disappointed.'